Variable-wavelength optical output device

ABSTRACT

In a wavelength-variable light outputting apparatus, a diffraction grating  8  and a shielding member  11  which make wavelength and light quantity variable are attached to galvanometric scanners  12, 13,  respectively, and the latter are swung, whereby the wavelength can be made variable at a high speed while in a state where the light quantity is kept constant. Such an apparatus is useful for capturing a fluorescent image of a biological sample in particular. By way of the shielding member  11,  light is made incident on the optical fiber  10  and is outputted therefrom, whereby a biological sample SM can effectively be irradiated with light.

TECHNICAL FIELD

The present invention relates to a wavelength-variable light outputtingapparatus for irradiating an object with light whose wavelength is madevariable.

BACKGROUND ART

A conventional wavelength-variable light outputting apparatus isdisclosed in Japanese Patent Application Laid-Open No. HEI 1-223929. Inthis apparatus, light outputted from a light source is made incident onan optical filter rotator having three colors of red (R), green (G), andblue (B), whereby light having a desirable wavelength is outputtedtherefrom. For controlling color light quantities independently fromeach other, it will be sufficient if a plurality of liquid crystalfilters, ND filters having respective light attenuation ratios differentfrom each other, and the like are arranged on the output side of eachoptical filter and switched therebetween.

DISCLOSURE OF THE INVENTION

The conventional wavelength-variable light outputting apparatus can beused for observing biological samples. Namely, when afluorescence-labeled biological sample disposed under a microscope isirradiated with monochromatic light having a selected wavelength aspumping light, fluorescence occurs from the biological sample. Thusgenerated fluorescence can be captured as a fluorescent image of thebiological sample.

Since the transmission or absorption wavelength band of a materialconstituting the sample varies depending on the kind of material, asample image reflecting the material constituting the sample can beobtained if the sample image is captured with variable wavelengths.

Since a plurality of wavelengths of light are necessary depending onkinds of fluorescence labels and sample-constituting materials, it isdesirable that wavelengths be rapidly changed and switched in order toshorten the measurement time. When combining images obtained uponirradiation with a plurality of wavelengths, in particular, it ispreferred that the irradiation light quantity be constant from theviewpoint of utility in analysis.

However, wavelength sweeping cannot be carried out at a high speed inthe above-mentioned conventional apparatus. Namely, the light from thelight source has a wavelength distribution, so that its light quantitydiffers from wavelength to wavelength, whereby it is necessary for aplurality of optical filters and ND filters provided independently fromeach other to rotate and move at a high speed in order to makewavelengths variable while maintaining a constant light quantity.However, continuous wavelength sweeping requires a number of filters,each of which has a large mass, so that a driving apparatus moving sucha structure while controlling its position can operate only at arelatively low speed.

In view of the problem mentioned above, it is an object of the presentinvention to provide a wavelength-variable light outputting apparatuswhich can make wavelengths variable at a high speed while controllinglight quantities.

For overcoming the above-mentioned problem, the present inventionprovides a wavelength-variable light outputting apparatus comprising alight source outputting light having a plurality of wavelengths, aswinging first galvanometric scanner provided with spectroscopic meansfor spectrally dividing the light outputted from the light source, aswinging second galvanometric scanner provided with a shielding orreflecting member adapted to block or reflect at least a part of lightoutputted from the spectroscopic means, and an optical fiber disposed ata position where light outputted from the spectroscopic means can bemade incident by way of the shielding or reflecting member.

The light outputted from the light source is fed into spectroscopicmeans such as a diffraction grating or prism. Since the spectroscopicmeans spectrally divides the light outputted from the light source, theemitting direction of a specific wavelength component among thus dividedlight components can be deflected by swinging the first galvanometricscanner. This specific wavelength component is made incident on theshielding or reflecting member, whereby a part thereof is blocked orreflected. Since such a member is provided with the second galvanometricscanner, the transmission light quantity or reflecting direction of thespecific wavelength component varies when the second galvanometricscanner is swung.

Since the optical fiber is disposed at a position where light outputtedfrom the spectroscopic means can be made incident by way of theshielding or reflecting member, the quantity of light finally incidenton the optical fiber can vary if the transmission light quantity is madevariable by the shielding member, whereas, due to the fact that theinput end face of the optical fiber has a core with a finite diameter,the quantity of light finally entering the core of the optical fiberwill vary if the reflecting direction is made variable by the reflectingmember.

Thus, since galvanometric scanners which can swing at a high speed areprovided with the spectroscopic means and the shielding or reflectingmember, this wavelength-variable light outputting apparatus can select aspecific wavelength component at a high speed and make its lightquantity variable at a high speed.

Preferably, this wavelength-variable light outputting apparatuscomprises storage means for storing respective swinging angles of thefirst and second galvanometric scanners and a relationship between thewavelength and quantity of light outputted from the optical fiber inresponse to a combination of the swinging angles, input means forinputting information concerning the wavelength and quantity of light tobe outputted from the optical fiber, and control means for reading outthe above-mentioned relationship from the storage means according to theinformation fed into the input means and controlling the swinging anglesof the first and second galvanometric scanners in response to therelationship.

The storage means such as a memory stores therein respective swingingangles of the first and second galvanometric scanners and a relationshipbetween the wavelength and quantity of light outputted from the opticalfiber in response to a combination of the swinging angles. Wheninformation concerning the wavelength and quantity of light to beoutputted from the optical fiber is fed into the input means such as akeyboard, the control means reads out the above-mentioned relationshipfrom the storage means according to the information fed into the inputmeans, and controls the swinging angles in response to thisrelationship. Namely, the wavelength and quantity of light outputtedfrom the optical fiber can definitely be determined according to acombination of swinging angles, whereby desirable light can be outputtedfrom the optical fiber based on the input to the input means alone.

Also, this wavelength-variable light outputting apparatus may comprisecontrol means for changing the wavelength of light outputted from theoptical fiber by changing a swinging angle of the first galvanometricscanner and changing a swinging angle of the second galvanometricscanner such that the quantity of the wavelength of light fed to theshielding or reflecting member in response to the swinging angle of thefirst galvanometric scanner and The ratio of incidence of light incidenton the optical fiber in response to the swinging angle of the secondgalvanometric scanner form a fixed product therebetween.

When the swinging angle of the first galvanometric scanner is changed,the wavelength of light outputted from the optical fiber changes. Thequantity of the wavelength of light fed to the shielding or reflectingmember varies depending on this swinging angle. In order for the lightfinally outputted from the optical fiber to become constant, it will besufficient if the quantity of the wavelength of light fed to theshielding or reflecting member in response to the swinging angle of thefirst galvanometric scanner and the ratio of incidence of the lightincident on the optical fiber in response to the swinging angle of thesecond galvanometric scanner form a fixed product therebetween.

The control means changes the swinging angle of the second galvanometricscanner so as to satisfy this relationship. If the swinging angle of thesecond galvanometric scanner for satisfying such a relationship isdetermined beforehand by use of a calculation or lookup table system,the time required for determining it can be shortened, whereby thewavelength can be made variable at a higher speed under a constant lightquantity. However, the swinging angle of the second galvanometricscanner may also be determined sequentially in response to the swingingangle of the first galvanometric scanner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is an explanatory view showing the configuration of awavelength-variable light outputting apparatus;

FIGS. 2A, 2B, and 2C are explanatory views showing relationships betweenpositions of a shielding member 11 and light incident on an opticalfiber 10;

FIG. 3 is a block diagram showing a system configuration of afluorescent image capturing apparatus using the above-mentionedwavelength-variable light outputting apparatus;

FIG. 4 is an explanatory view showing the configuration of thewavelength-variable light outputting apparatus in accordance withanother embodiment;

FIGS. 5A, 5B, and 5C are explanatory views showing positionalrelationships between the input end face (core) F of the optical fiber10 and a light-collecting spot S;

FIG. 6 is a graph showing the change in quantity (intensity) of lightoutputted from the optical fiber 10 with time when light incidence ratioβ was changed from 100% to 50%; and

FIG. 7 is a graph showing the change in quantity (intensity) of lightoutputted from the optical fiber 10 with time when light incidence ratioβ was changed from 100% to 0%.

BEST MODES FOR CARRYING OUT THE INVENTION

In the following, wavelength-variable light outputting apparatus inaccordance with embodiments will be explained. In the explanation,constituents identical to each other will be referred to with numeralsidentical to each other without repeating their overlappingdescriptions.

FIG. 1 is an explanatory view showing the configuration of awavelength-variable light outputting apparatus. This wavelength-variablelight outputting apparatus is constituted by a light source section 100for emitting light, and a spectroscopic section 101 for spectrallydividing the emitted light while adjusting the light quantity thereof.This will be explained in more detail.

The wavelength-variable light outputting apparatus comprises a lightsource 1 such as an Xe lamp. Though the light outputted from the lightsource 1 diverges in all directions, it is reflected to the front sideof the light source 1 by a small concave reflecting mirror 2 disposed soas to face the light source 1 on the back side (left side in thedrawing) thereof, and is made incident on a large concave reflectingmirror 4 by way of a lens 3 together with the light directly emittedfrom the light source 1 to the front side.

A convex reflecting mirror 5 is disposed near the center of curvature ofthe concave reflecting mirror 4, so that the light reflected by theconcave reflecting mirror 4 is reflected again toward the concavereflecting mirror 4. The light reflected twice by the concave reflectingmirror 4 is converged at a position where an entrance slit 6 isdisposed, and passes through the slit 6. The light emitted from the slit6 is collimated by an off-axis parabolic mirror 7, so as to irradiate adiffraction grating (spectroscopic means) 8 which is rotatably movable.

The light irradiated on the diffraction grating 8 is spectrally dividedinto separate wavelength components which are made incident on theoff-axis parabolic mirror 9, and are converged thereby onto an input endface of an optical fiber 10. A rotatably movable shielding member 11 isdisposed in an optical path between the off-axis parabolic mirror 9 andthe optical fiber 10. The light converged onto the input end face of theoptical fiber 10 passes through the optical fiber 10, so as to beoutputted from the output end face thereof.

The diffraction grating 8 is attached to a first galvanometric scanner12, whereas the first galvanometric scanner 12 swings the diffractiongrating 8 while using an axis perpendicular to the optical axis of lightincident on the diffraction grating 8 as the axis of swinging. When thediffraction grating 8 is swung by driving the first galvanometricscanner 12, the advancing direction of a specific wavelength componentoutputted from the diffraction grating 8 is deflected, whereby the lightfed to the optical fiber 10 changes its wavelength.

The light-shielding member 11 disposed in the optical path leading tothe optical fiber 10 is attached to a second galvanometric scanner 13,which swings the light-shielding member 11 while using an axisperpendicular to the optical axis of light incident on the optical fiber10 as the axis of swinging. When the second galvanometric scanner 13 isdriven so as to swing the light-shielding member 11, the light incidenton the optical fiber 10 is partly blocked by the shielding member 11,whereby the quantity of light fed into the optical fiber 10 changes.

FIGS. 2A, 2B, and 2C are explanatory views showing relationships betweenpositions of the shielding member 11 and light incident on the opticalfiber 10. As shown in these drawings, the swinging axis of the secondgalvanometric scanner 13 does not intersect the optical axis of theoptical fiber 10, but is positioned outside the effective diameter,perpendicular to the optical axis, of the light converged onto the inputend face of the optical fiber 10.

When the whole light-shielding member 11 is positioned outside theconvergent light as shown in FIG. 2A, 100% of the convergent lightenters the optical fiber 10 (incidence ratio β=100%).

When an outer edge of the light-shielding member 11 on the optical axisside is positioned on the optical axis of the convergent light as shownin FIG. 2B, 50% of the convergent light enters the optical fiber 10(incidence ratio β=50%).

When the whole light-shielding member 11 is positioned within theoptical path of the convergent light as shown in FIG. 2C, 0% of theconvergent light enters the optical fiber 10 (incidence ratio β=0%).

Thus, the swinging angle θ2 of the light-shielding member 11 and theincidence ratio β of convergent light correspond to each other one toone. Similarly, the swinging angle θ1 of the diffraction grating 8 andthe emission angle of output light from the diffraction grating 8, i.e.,the advancing direction of a specific wavelength component, correspondto each other one to one. The diffraction grating 8 can be replaced by aprism which spectrally divides light in a similar fashion.

FIG. 3 is a block diagram showing a system configuration of afluorescent image capturing apparatus using the above-mentionedwavelength-variable light outputting apparatus. This fluorescent imagecapturing apparatus combines the wavelength-variable light outputtingapparatus with an imaging device 14. Namely, in this apparatus, afluorescence-labeled biological sample SM is irradiated with lightemitted from the optical fiber 10, and a fluorescent image of the samplegenerated upon the irradiation is captured by the imaging device 14.

This diagram shows a control unit (control means) 15 for controlling thelight source 1 and scanners 12, 13 in the wavelength-variable lightoutputting apparatus; a storage device (storage means) 16 such as amemory for storing control conditions effected by the control unit 15,an input device (input means) 17 such as a keyboard with which anoperator inputs operations of the wavelength-variable light outputtingapparatus, and a display 18 for displaying the information about inputto the input device 17 and the image captured by the imaging device 14.

The storage device 16 in this apparatus stores the respective swingingangles 01, 02 of the first and second galvanometric scanners 12, 13 andthe relationship ((θ1, θ2)=(λ, E)) between the wavelength λ and quantityE of light outputted from the optical fiber 10 in response to thecombination of the swinging angles θ1, θ2. Here, the wavelength refersto the center wavelength.

Information (λ, E) concerning the wavelength λ and quantity E of lightto be outputted from the optical fiber 10 is fed into the input device17.

According to the information (λ, E) fed into the input device 17, thecontrol unit 15 reads out the relationship ((λ, E)=(λ1, λ2)) from thestorage device 16, and controls the swinging angles λ1, λ2 of the firstand second galvanometric scanners 12, 13 in conformity to thisrelationship. Namely, (θ1, θ2) is determined so as to match target (λ,E), and the first and second galvanometric scanners 12, 13 are driven soas to attain (λ1, λ2). Thereafter, the control unit 15 turns on thelight source 1 or carries out the driving while turning on the lightsource 1.

Namely, this apparatus can definitely determine the wavelength λ andquantity E of light to be outputted from the optical fiber 10 accordingto the combination of swinging angles (θ1, θ2), thereby being able tooutput desirable light from the optical fiber 10 in response to theinput to the input device 17 alone.

The following table shows the center wavelength (nm) and half width (nm)of light emitted from the optical fiber 10 in the case where thequantity of light (output) (mW) is made variable at each of wavelengthsλ of 380 nm, 500 nm, and 650 nm.

λ = 380 nm λ = 500 nm λ = 650 nm center center center output wavelengthhalf output wavelength half output wavelength half (mW) (nm) width (mW)(nm) width (mW) (nm) width 2.88 380.1 15.5 3.32 500.2 14.4 1.25 650.013.7 2.61 380.1 15.4 3.00 500.2 14.6 1.12 650.0 13.7 2.32 380.1 15.62.67 500.2 14.7 1.00 650.0 13.7 2.02 380.1 15.5 2.32 500.2 14.5 0.88650.0 13.7 1.74 380.1 15.5 1.98 500.2 14.6 0.75 650.0 13.7 1.43 380.115.5 1.65 500.2 14.3 0.62 650.0 13.5 1.16 380.1 15.2 1.32 500.2 14.30.50 650.0 13.5 0.87 380.1 15.1 1.00 500.2 14.1 0.37 650.0 13.0 0.57380.1 15.0 0.66 500.7 13.8 0.25 650.0 12.5 0.25 380.1 14.3 0.29 501.213.1 0.11 650.0 11.7

As can be seen from this table, it is verified in this apparatus thatchanges in light quantity do not alter the center wavelength, and hardlyvary the half width.

While altering the output light wavelength λ from the optical fiber 10by changing the swinging angle θ1 of the first galvanometric scanner 12,the swinging angle θ2 of the second galvanometric scanner 13 may bechanged such that the product of the light quantity e of the wavelengthof light fed to the shielding member 11 or a reflecting member 11′,which will be explained later, in response to the swinging angle θ1, andthe ratio of incidence β of light incident on the optical fiber 10 inresponse to the swinging angle θ2 of the second optical fiber 10,(e×β)=E, becomes constant.

When the swinging angle el of the first galvanometric scanner 12 isaltered, the output light wavelength λ from the optical fiber 10changes. Since the light emitted from the light source 1 has awavelength distribution, the light quantity e of the wavelength of lightfed to the shielding or reflecting member 11, 11′ in response to theswinging angle θ1 varies. For making the quantity E of light finallyoutputted from the optical fiber 10 constant, it will be sufficient ifthe light quantity e of the wavelength of light fed to the shielding orreflecting member 11, 11′ in response to the swinging angle θ1 of thefirst galvanometric scanner 12, and the incidence ratio β of the lightincident on the optical fiber 10 in response to the swinging angle θ2 ofthe second galvanometric scanner 13 form a fixed product therebetween.

The control unit 15 changes the swinging angle θ2 of the secondgalvanometric scanner 13 so as to satisfy the above-mentionedrelationship. If the swinging angle θ2 of the second galvanometricscanner 13 for satisfying such a relationship is determined beforehandby use of a calculation or lookup table system, the time required fordetermining it can be shortened, whereby the wavelength can be madevariable at a higher speed under a constant light quantity. However, theswinging angle θ2 of the second galvanometric scanner 13 can bedetermined sequentially in response to the swinging angle θ1 of thefirst galvanometric scanner 12.

Finally, the light quantity control using the reflecting member 11′ willbe explained.

FIG. 4 is an explanatory view showing the configuration of thewavelength-variable light outputting apparatus in accordance withanother embodiment. This apparatus differs from that of theabove-mentioned one only in that the member provided in the secondgalvanometric scanner 2 is not the shielding member 11 but thereflecting member 11′, and that the swinging axis of the secondgalvanometric scanner 13 is disposed oblique with respect to the opticalaxis of light incident on the reflecting member 11′.

Namely, a specific wavelength component in the light spectrally dividedby the diffraction grating 8 is converged by an off-axis parabolicmirror 9, and is reflected by the reflecting member 11′ disposed in theoptical path between the off-axis parabolic mirror 9 and the opticalfiber 10, so as to be converged onto the input end face F of the opticalfiber 10 (S being a spot of converged light) . Therefore, due to theswinging of the second galvanometric scanner 13, the position oflight-collecting spot S moves, whereby the light incidence ratio β tothe optical fiber changes.

FIGS. 5A, SB, and 5C are explanatory views showing positionalrelationships between the input end face (core) F of the optical fiber10 and the light-collecting spot S.

When the position of converged light spot S and the position of opticalfiber end face F coincide with each other, i.e., their centers ofgravity coincide with each other, so that the spot S and the end face Fcompletely overlay each other as shown in FIG. 5A, the light incidenceratio β is 100%.

When the position of converged light spot S and the position of opticalfiber end face F slightly deviate from each other, i.e., their centersof gravity shift from each other, so that the spot S and end face Fpartly overlap each other as shown in FIGS. 5B and 5C, the lightincidence ratio β is greater than 0% but smaller than 100%. When nooverlap exists, the light incidence ratio β is 0%.

Thus, in this embodiment, the second galvanometric scanner 13 is drivenso as to swing the reflecting member 11′, whereby the light incidenceratio β can be changed.

The quantity of light outputted from the optical fiber 10 in thewavelength-variable light outputting apparatus in the former embodimentwas measured at a wavelength of 380 nm. Here, for verifying whetherhigh-speed variation was possible or not, the light incidence ratio βwas changed by driving the second galvanometric scanner 13.

FIG. 6 is a graph showing the change in quantity (intensity) of lightoutputted from the optical fiber 10 with time when the light incidenceratio β was changed from 100% to 50%.

FIG. 7 is a graph showing the change in quantity (intensity) of lightoutputted from the optical fiber 10 with time when the light incidenceratio β was changed from 100% to 0%. These light quantities weredetected by a photodiode.

In both graphs, signals in the upper half indicate the quantity of light(2 V/div), whereas signals in the lower half indicate driving signalsfed into the second galvanometric scanner 13 (5 V/div), with a temporalaxis of 2 ms/div. These graphs have proved that changes in lightquantity can be completed in a short time of 2 ms or less after theapplication of driving signals in both cases.

The above-mentioned wavelength-variable light outputting apparatus canbe applied not only to the fluorescent image capturing apparatus, butalso to a transmitted or absorbed light image capturing apparatus foryielding a sample image reflecting a sample-constituting material if thesample image is captured at variable wavelengths. The images obtained atthese plurality of wavelengths can be combined by the control unit 15shown in FIG. 3, so as to be displayed on the display 18.

As explained in the foregoing, the above-mentioned wavelength-variablelight outputting apparatus comprises the light source 1 outputting lighthaving a plurality of wavelengths, the swinging first galvanometricscanner 12 provided with the spectroscopic means 8 for spectrallydividing the light outputted from the light source 1, the swingingsecond galvanometric scanner 13 provided with the shielding member 11 orreflecting member 11′ adapted to block or reflect at least a part oflight outputted from the spectroscopic means 8, and the optical fiber 10disposed at a position where light outputted from the spectroscopicmeans 8 can be made incident by way of the shielding or reflectingmember 11, 11′.

The light outputted from the light source 1 is fed into spectroscopicmeans 8 such as a diffraction grating or prism. Since the spectroscopicmeans 8 spectrally divides the light outputted from the light source 1,the emitting direction of a specific wavelength component among thusdivided light components can be deflected by swinging the firstgalvanometric scanner 12. This specific wavelength component is madeincident on the shielding member 11 or reflecting member 11′, whereby apart thereof is blocked or reflected. Since such a member is providedwith the second galvanometric scanner 13, the transmission lightquantity or reflecting direction of the specific wavelength component isvariable when the second galvanometric scanner 13 is swung.

Since the optical fiber 10 is disposed at a position where lightoutputted from the spectroscopic means 8 can be made incident by way ofthe shielding or reflecting member 11, 11′, the quantity of lightfinally incident on the optical fiber 10 can vary if the transmissionlight quantity is made variable by the shielding member 11 whereas, dueto the fact that the input end face F of the optical fiber 10 has a corewith a finite diameter, the quantity of light finally entering the coreof the optical fiber 10 will vary if the reflecting direction is madevariable by the reflecting member 11′.

Thus, since the galvanometric scanners 12, 13, which can swing at a highspeed are provided with the spectroscopic means 8 and the shielding orreflecting member 11, 11′, respectively, the above-mentionedwavelength-variable light outputting apparatus can select a specificwavelength component at a high speed and make its light quantityvariable at a high speed. As mentioned above, such an apparatus isuseful for capturing a fluorescent image of the biological sample SM. Byway of the shielding member 11, light is made incident on the opticalfiber 10 and is outputted therefrom, whereby the biological sample SMcan effectively be irradiated with light.

The present invention can provide a wavelength-variable light outputtingapparatus which can make wavelengths variable at a high speed whilecontrolling light quantities.

INDUSTRIAL APPLICABILITY

The present invention can be utilized in a wavelength-variable lightoutputting apparatus for irradiating an object with light whosewavelength is made variable.

1. A wavelength-variable light outputting apparatus comprising: a lightsource outputting light having a plurality of wavelengths; a swingingfirst galvanometric scanner provided with spectroscopic means forspectrally dividing said light outputted from said light source; aswinging second galvanometric scanner provided with a shielding orreflecting member adapted to block or reflect at least a part of lightoutputted from said spectroscopic means, wherein said swinging first andsecond galvanometric scanners have swinging axes that extend indifferent directions from each other; an optical fiber disposed at aposition where light outputted from said spectroscopic means can be madeincident by way of said shielding or reflecting member; and a controlunit that controls said swinging first and second galvanometricscanners, said swinging second galvanometric scanner being controlled soas to control a quantity of light incident on said optical fiber, thequantity of light incident on the optical fiber varying in accordancewith the transmission or reflection of light by said shielding orreflecting member, respectively.
 2. A wavelength-variable lightoutputting apparatus according to claim 1, comprising: storage means forstoring respective swinging angles of said first and secondgalvanometric scanners and a relationship between wavelength andquantity of light outputted from said optical fiber in response to acombination of said swinging angles; input means for inputtinginformation concerning wavelength and quantity of light to be outputtedfrom said optical fiber; and said control means reading out saidrelationship from said storage means according to said information fedinto said input means and controlling said swinging angles of said firstand second galvanometric scanners in response to said relationship.
 3. Awavelength-variable light outputting apparatus according to claim 1,said control means changing a wavelength of light outputted from saidoptical fiber by changing a swinging angle of said first galvanometricscanner and changing a swinging angle of said second galvanometricscanner such that the quantity of said wavelength of light fed to saidshielding or reflecting member in response to said swinging angle ofsaid first galvanometric scanner and the ratio of incidence of lightincident on said optical fiber in response to said swinging angle ofsaid second galvanometric scanner form a fixed product therebetween. 4.A wavelength-variable light outputting apparatus according to claim 1,wherein said shielding or reflecting member partially blocks or reflectsthe light from said spectroscopic means.
 5. A wavelength variable lightoutputting apparatus according to claim 1, wherein said swinging firstand second galvanometric scanners have swinging axes that extend indifferent directions that are substantially perpendicular to each other.6. A wavelength variable light outputting apparatus according to claim1, wherein said swinging second galvanometric scanner is controlled soas to continuously control the quantity of light incident on saidoptical fiber.